Electrical-lamp lock.



W. C. KERCH. ELECTRICAL LAMP LOCK.

APPLICATION FILED JULY 24. I916.

1,238,684. Patented Au .j'- 2s,1@17

. WITNESSES: INVENTOR Awro RNnYs Mill \'allev.

tlN l1 PATET l WILLIAM C. KERGH, OF MILL VALLEY, CALIFORNIA, ASSIGNOR OE ONE-HALF TO CHARLES ROTHSCHILD AND ONE-HALF TO SAMUEL DTJ'SENBERRY, BOTH OF SAN FRANCISCO, CALIFORNIA.

ELECTRICAL-LAMP LOCK.

\ Specification of Letters Patent. Patented Aug. 28, 1917.

Application fiIed July 24, 1916. Serial No. 110,881.

To all whom it may concern:

Be it known that I. WILLIAM C. Kunon, a citizen ol the United States. residing at in the county of Maria and State of California, have invented a new and useful Improvement in I)lectrical-Lamp Locks. of which the following is a specifiea tion. I

This invent ion relates to a means for locking electric globes or lamps within the sockets in such a manner. that the globe cannot be detached from the socket after having once been introdiuaal. without breaking. the

object being to prevent illegal removal of such globes.

This invention consists of a clutch adapted to fit between the lamp base and socket, the clutch comprising a corrugated extension which when intrmluced. lies within and engages the sides of the socket so that it cannot be removed therefrom. .TiVithin this clutch. is a coiled elastic ring within which the metal base of the lamp may be introduced. and when so introduced it is locked in place by means ot a sharp engaging tongue turned inwardly. A suitable insulating material may be introduced between the clutch and the elastic interior band.

it also includes details 0? construction which will be more fully explained by reference to the accompanying drawing in which Figure 1 shows the device attached bulb and locked in the socket.

Fig. 2 is a perspective of the locking de vice.

Fig. 3 is a section through the device showing the lock inelevation.

Fig. 4 is av plan view of the device.

to a

Fig. 5 is a view of the curved corrugated plate.

Considerable annoyance and loss is experienced especially in public places, by the surreptitious unscrewing and taking away oi the electric lamps by unprincipled persons. and it is the object ol my invention to lock these lamps in place so that they cannot be removed except by breaking and destroying them. As shown in the drawing. represents an electric. lamp ot' a character oi this kind having a screw-threaded metal base 2. 3 is a permanent screw-threaded socket into which the lamp base is screwed until electric contactis made, so that the through it to engage lamp may he energized by turning the proper key, not here shown.

As here shown my locking device consists of a rm 9; 4 having an arm 5 fixed to an intel'l()l' coiled spring 6 and projecting from it as shown. The ring 4 is of suchsize that the. metal base oi the lamp may be inserted v the socket 3, against the end of which the ring 4 is held and the arm 5 which I have here shown as corrugated and curved transversely in an opposite direction from the curvature of the ring. thus projects into the socket with the concavit toward the interior of the socket. This clutch arm is preferably made of steel and suliicicntly hardto hold its edges in sharp condition, and by reason of its concavity opposed to that of the socket, when the lamp has been screwed into the socket, these edges will bite into the softer material or the socket and will thus prevent its being turned or pulled out. Within the insulating ring is fixed an elastic coiled spring 6. This spring is formed of a single coil the ends overlap slightly and it is of such size that; when the socket is to be connected, the lamp base is introduced into the coil and screwed or otherwise inserted to its permanent position. The'inncr coil of the spring is formed with a sharp projecting edge 7 bent outward to allow the lamp base to pass when screwed in but which bites into the material of the base of the lamp when it is attempted to unscrew it and thus holds it so that it cannot be unscrewed and taken 0E because this engaging edge or tongue holds it in place, and any effort to turn it in such a manner as to remove it from the socket will cansethe spring to contract against the exterior of the base and thus hold the base and lamp firmly in place. The insulating ring 8 is introduccd between the spring 6 and the ring 4 as shown at 8. The arm 5 and the fixed end of the spring 6 are secured to the insulating ring 8.

The lamp is thus held in position when once inserted and cannot be removed until the glass of the lamp is broken and the lamp socket, thus clamping the arm 5 between the base and the socket, so that. its sharp edges will engage the socket and prevent. its turning. When the lamp base is screwed into c the socket, the action will be to allow the threaded lamp base to pass the free end of the fixed springt so as to allow the lamp to be screwed up to its ll? an attempt. is made to unscrew the lamp the bent end of the spring engages the base and forces the sharp edge 7 to bite into the base, and thus coiled spring, a. corrugated plate fixed to said spring and projecting upward within the socket, said plate having a curvature transversely which is opposed to that of the socket and sharpened edges which engage the interior of the socket, said coiled spring having one end tixcd within the ring, and its free inner end bent. inward and sharpened to engage the lamp base and prevent it from unscrewing.

2. in a locking device for electric lamps of the character described, a ring abutting against. the end of a lamp socket and havi ig an interior ring of insulating material, an upwardty extending sharp edged plate engaging the interior of the lamp socket, and an elastic spring coiled interiorly to the in sulating ring and having an inturned free end adapted to engage the lamp base to prevent it being unscrewed. I

In testimony whercol l have hereunto set my hand in the presence of two subscribing witnesses.

WILLIAM U. KERUH.

Witnesses:

Geo. ll. STRONG, FRANCES V. COLE. 

